This renewal application seeks continued support for years 26-30 of the Washington University Training Program in Immunology and Immunogenetics. Washington University has made a strong and lasting commitment to Immunology research and training through the development of both an Immunology Graduate Program, responsible for directing graduate education in Immunology and a University-recognized Center for Immunology, responsible for coordinating the Immunology-related activities of the 51 faculty, 140 postdoctoral fellows and 63 graduate students that constitute our Immunology community. The Immunology community at Washington University has achieved a world-recognized status. It is characterized by a collaborative atmosphere that has helped establish an excellent environment for training young Immunologists. This grant and the Washington University Immunology Community have formed a symbiotic relationship where the growth of the community has been catalyzed through the benefits of trainee support afforded by this training grant and the quality of our training program has been enhanced by the growth and interactive nature of the community. This program contains elements that insure the appropriate training of Immunologists at both the predoctoral and postdoctoral levels. Fundamental laboratory research resides at the center of the training experience for both types of candidates. A total of 30 Immunology research faculty are listed on this grant but trainees can work with any of the 51 Immunologists in residence at Washington University. In addition, all trainees participate in University-wide Immunology seminars, journal clubs, work-in-progress meetings and retreats. Predoctoral trainees must complete and show competence in a rigorous curriculum of basic training where they are exposed, through formalized classroom experiences, to historical, modern and emerging concepts of Immunology, related biomedical sciences and research ethics. Moreover, we now offer our trainees a unique opportunity to see the translational aspects of immunology through a novel Human Immunobiology Pathway course that we developed during the last funding period that pairs Ph.D. candidates with clinical immunology faculty who bring the students right to the patient bedside. To insure continuity of the comprehensive Immunology training experience that has been established at this institution, we request renewal of our 10 predoctoral and 10 postdoctoral trainee slots, a number that is unchanged from that of the current funding period.